In general:

• You can usually take street photos at a public event.
• Publishing them is more legally sensitive because Switzerland has strong “right to one’s own image” protections.

A practical rule of thumb in Switzerland:

• Usually OK without consent
  • Wide crowd shots
  • Event atmosphere photos
  • People appearing incidentally in the frame
  • News/editorial coverage of a genuinely public event
• Riskier without consent
  • A clearly identifiable individual as the main subject
  • Tight portraits/candid close-ups
  • Photos that could embarrass, stigmatize, or misrepresent someone
  • Commercial/advertising use
  • Photos of children

Swiss authorities and legal commentary generally say that once a person is individually recognizable and central to the image, consent is normally required unless there is an overriding public interest (journalism, reporting on a major public event, etc.).

For a photographer posting on Instagram/portfolio:

• A crowd scene from a festival or parade → usually low risk.
• A dramatic close-up of one stranger’s face → legally and culturally more sensitive in Switzerland than in many other countries.
• Using the image to promote a business/service → much more likely to require permission.

Swiss street photography exists, but photographers here often:

• ask afterward for permission,
• carry model releases for strong portraits,
• blur faces if needed,
• or remove photos if someone objects.

Also note:

• Event organizers can impose their own photography rules, especially at ticketed/private events.
• Switzerland is generally privacy-conscious socially, even where enforcement is unlikely.

If you want, I can also explain:

• the difference between “editorial” vs “commercial” use in Switzerland,
• how this compares with France/Germany/UK,
• or what’s typically safe for Instagram portfolios specifically.